Finally, a pile up of reports at boundaries could involve temporal memory, but not hierarchical organization. Temporal coding might be most accurate near semester boundaries, because these are landmarks. In space, locating objects is more accurate near landmarks (e.g., Kosslyn, Pick, & Fariello, 1974; Nelson & Chaiklin, 1980; Newcombe & Liben, 1982; Thorndyke, 1981). If temporal coding is more accurate at the beginnings and ends of semesters, reports would include both events that actually occurred then, plus other events misplaced there because of greater coding inaccuracy at other times. Use of landmarks at retrieval to improve dating accuracy was found by several investigators (e.g., Baddeley et aI., 1978; Brown et aI., 1986; Friedman & Wilkins, 1985; Loftus & Marburger, 1983; Thompson, 1982).